Frame for lamp resistances



H. D. ROHMAN.

FRAME FOR LAMP RESISTANCES.

APPLICATION FILED MAR. 20, 1917.

1,349,583. Patented Aug. 17, 1920.

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3 l l l l lfli l b l l 2Q OH 45 2 2 H. D. ROHMAN; FBAME FOR LAMP RESISTANCES.

APPLICATION FILED MAR. 20' I917.

Patented Aug. 17, 1920.

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fi/ MgI ENTOR j lffOR/YE Y2 UNITED STATES PATENT OFFICE.

HARRY D. ROHMAN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO J. STONE & COMPANY, LIMITED, 0F DEPTFORD, ENGLAND.

FRAME FOR LAMP RESISTANCES.

Specification of Letters Patent.

Patented Aug. 17, 1920.

Application filed March 20, 1917. Serial No. 155,968.

To all whom it may concern Be it known that I, HARRY D. ROHMAN, a citizen of the Republic of Switzerland, residin at New York cit in the county of New York and State of Flew York, have invented certain new and useful Improvements in Frames for Lamp Resistances, of which the following is a specification.

This invention relates to frames for lamp resistances or similar voltage controlling elements such as are used, for example, in electric lighting and heating systems for railway and other vehicles, and it has for one of its primary objects the provision of an improved device of the character specified which is readily adaptable to any one of a number of ditierent arrangements of the sys tem or to changes in the system. Another of the objects resides in the provision ofa device of the character described in which the resistance elements may be readily inserted and removed, and in which but a minimum number of parts is required.

A further object of the invention resides in the provision of a simple frame of the character described which can be readily installed in connection with or attached to standard panel boards for lighting and heating systems in such manner that the resistance elements are readily accessible, and yet protected.

The foregoing, together with such other objects as may hereinafter appear, or are incident to my invention, I obtain by means of an improved construction, the preferred embodiment of which I have shown in the accompanying drawings, wherein Figure 1 is a diagram of a car lighting system showing my improvements applied thereto; Fig. 2 is a rear elevation and partial section through my improved frame; Fig. 3 is an end elevation of Fig. 1; Fig. 4 is a plan view of Fig. 1 and Fig. 5 is a sectional view of a modification of my invention.

In order that my invention may be better understood, I shall first describe the system to which I have shown it applied, reference being had to Fig. 1. The reference numeral 7 indicates the usual primary generator or dynamo which is driven from a car axle bythe usual driving mechanism, such as a belt. The groups of lamps C, D, and E indicate translating circuits such as lamp circuits, and of which there may be any number, depending upon the particular service for which the car is being used. The dynamo is arranged to supply such lamps when the train is running at or above a critical train speed, such for example as 15 miles per hour, and when the train is at rest or is traveling below such speed, the translating circuits are supplied by the units A and B of a two-unit battery. The generator positive lead is indicated by the numeral 8, and the generator negative return by the reference numeral 9. Located in the generator positive 8 is a cut-in switch F havin the usual series coil 8' and shunt coil 10 whereby, when the dynamo develops a voltage equal to or greater than that of the battery, the cut-in switch will be closed, com pleting the circuit, and when the dynamo voltage drops below that of the battery, the switch will be opened, as is well understood in this art. Beyond the series coil 8' the positive lead 8 divides, one branch leading directly to the change-over switch G and the other branch, 8*, leads to the bus-bar 11 of my improved lamp resistance frame, which is indicated, as a whole, by the refercnce letter H. The positive leads 12 and 1 5 of the respective battery units A and B are connected to terminals in the changeover switch in the usual manner. A fourth wire 14; connects a terminal of the change over switch to the bus-bar 15 of lamp frame H, to which bus-bar a positive 16 for the various groups of lamps C, D, and E is con nected. The lamp circuits are controlled by a main lamp switch I, and each individual circuit is controlled by a two-pole single throw switch 2'.

The bus-bars 11 and 15 are connected by a main permanent resistance 17 which serves as a lamp resistance for the group of lamps G and at the same time serves to divert a portion of the dynamo current to charge the particular unit of the battery on charge. A

supplemental resistance 18 is connected to the bus-bar l1 and to the wire 19 which is connected to the positive of circuit D in advance of the lamps; and a second supplemental resistance 20 is connected to the busbar 11 and to the positive of the group of lamps E by the wire 21. A fourth and relatively weak resistance 22 is connected to the bus-bar 15 and to terminal 23 by wire 24. The contact 23 is adapted to be engaged by a yielding brush 25 in electrical connection with the generator positive 8 when the cut-in switch is closed, contact between the brush and the contact 23 being open when the cut-in switch is closed. The operation is as follows, assuming that the main lamp switch I is closed and that the switch 2' completing the circuit C is also closed. Current from the dynamo, assuming that the 'train is traveling at or above the critical speed, will pass through wire 8, wire 8, to the bus-bar 11, through resistance 17 to the bus-bar 15, thence via wire 16 and switch 2' to the positive of the circuit C, returning by wire 26 to the common negative 9. A. portion of the current will be supplied to unit A of the battery via wire 8, cut-in switch G and wire 12. The other unit of the battery will be in floating position and current may, in the event that the dynamo supply is insufficient, flow from unit B by way of wire 13, eut-in switch (l and wire 14 to the positive 16 of the lamps, the circuit being completed by the wire 26 and the common negative 9.

Now assuming that the switch of circuit D be closed to light the lamps of such circuit, current from the dynamo will charge unit A and supply circuit C in the manner hereinbefore pointed out, but a portion of the current will divide and pass through re' sistance 18, wire 19 to the positive of circuit D, the circuit being completed through the negative of such circuit, wire 26, and the common negative return 9. The switch 2' connects the resistances 17 and 18 in parallel and the resistances are so proportioned that the total resistance will be deerease to correspond with the increased lamp load, so that the lamp voltage will remain sub stantially constant, thereby eliminating any flick on the lamps.

If switch 2' for circuit E be now closed, the dynamo will supply circuits (1 and D in the manner described, but a portion of the current will divide and pass through resistance 20, wire 21, to the positive of circuit E, returning via wire 26 to the common negative 9. Three resistances, 17, 18, and 20, will now be connected in parallel, there by decreasing the total lamp resistance in direct proportion to the increased lamp load, thereby maintaining the voltage on the lamps substantially constant and eliminating any flick.

Assuming now that the train is at rest or is traveling below the critical speed. The cut-in switch is then open and current from unit B will supply the lamps through wire 13, cut-in switch G, wire ll, wire 16, returning by way of wire 26 to the negative 9 and battery. Current from unit A will also supply the lamps via wire 12, change-over switch G, wire 8, brush 25, contact 23, wire 24, resistance 22, bus-bar 15, and wire 16. The resistances 17, 18, and 20 are shortcircuited by the brush 25, contact 28, wire 24, and resistance 22, when the cut-in switch is open. maintain constant lamp voltage, because it will be seen that the battery which is on charge at the time the cut-in switch opens will have a higher voltage than the other unit of the battery, and this resistance 22 takes care of this relatively higher voltage and prevents any flick on the lamps.

When the main lamp switch 1 is open, contact is directly made between bus bar 11 and wires 16 and M through wire 27 and the extension 28, extension28 being uncer the control of the switch T, Therefore, the re sistance 17 is short-circuited by means of the wire 27 which is connected to the busbar 11. by Xtension 28 on the switch I and wire 16. When switch I is closed, direct contact is broken between wire 27 and eX- tension 28. The batteries are thus connected in parallel so that the dynamo will charge the two units of the battery in parallel, the dynamo current dividing just beyond the series coil 8 and supplying one battery by means of wire 8 and change-over switch G, and the other battery by wire 8, bus-bar 11, wire 27, extension 28, wire 16, wire 1%, and the change-over switch G, the circuit being completed by the common negative 9.

The system has been thus briefly described in order that the improvements with reference to the frame taking care of the various lamp resistances and connections hereinbefore noted, may be better under stood. 2 to 4t.

From inspection of these figures it will be seen that the frame H comprises the two bus-bars 11 and 15, such bars being preferably angle shaped members. The ends of the frame are closed by the end members 29 and 30 which are secured to the ends of the bus-bars by means of the studs 81, the end members being insulated from the bus-bars by means of the insulation 32, and the studs being insulated by means of the insulating sleeves 33 and insulating disks 341-. At the bottom of'each end member 36 is a base piece 35 adapted to serve as a means for attaching the frame H to the corner brackets which are utilized in fastening the panel board 87 in position. At correspondingly spaced intervals the two bus-bars 11 and 15 are provided with threaded openin adapted to receive the screws 39, such screws performing a double function, as will appear.

The various resistances heretofore described may be of any preferred form but are usually made up in the form of porcelain tubes, that is to say, the resistan e coils are embedded in a cylinder or tube of suitable insulating material. The improved frame is particularly adapted to receive this form of resistance tube, because the bushars 11 and 15 are spaced apart so that the Attention is now directed to The resistance 22 is provided to tubes maybe readily slipped into position between the busbars, in which position they are secured by means of the screws 39 which project within the tubes in the manner indicated in F ig. 2. The resistances 17, 18, 20 and 22, indicated diagrammatically in Fig. 1, are shown in side elevation in Fig. 2, as actually used. Resistance 17 is the main lamp rrsis re, and the ends of this resistance are wrapped around the screws 39, which screws, in addition to holding the tube, serve as terminals, respectively establishing electrical connection between the ends oi the resistance and the bus-bars 11 and 15. Resistance has one end in electrical connection with the busbar 15 by means of its respective holding screw 39, but the other end of the resistance is connected to the wire 21 leading to contact Resistances 18 and 20 have their lower ends in electrical cenne-fion with the bus-bar 11 by means oi their respective holding screws 39. The other end of resistance 18 is connected to the terminal lt) mounted on, but insulated from, the end member 30 of the frame, by means of the wire 41. ire 19 which leads to the positive of lamp circuit E is also connected to terminal. ll). The other end of resistance 20 is connected to a similar terminal 42 mounted. on, but insulated from, the end member 29 ot the frame by means of a wire 13. The wire 21 which leads to the positive of lamp circuit D is also connected to terminal 42. The branch 8 of the gene rator positive 8 13 connected to the ter piece 41-4, which in turn is secured to l. par 11 so as to be in electrical connection therewith. By means of wire 8 and terminal piece 44-, current from the dynamo reaches bus-bar ll and is distributed in the manner described. \Vire H is connected to bus-bar 15 by means of the terminal piece 45, which terminal pie'e is fastened to the bus-bar 15 by means of a screw 46, there being interposed between the terminal piece and the bus-bar a tiller plate 47, all so arranged that there is electrical connection between the terminal piece 45 and the bus-bar 15. The terminal piece 41:5 has no electrical connection with the bus-bar 1]. The lamp positive 16 is preferably conneztcd to the terminal piece 45.

From the foregoing it will be seen that the frame H is of very simple character and can be readily installed on standard panel boards for car lighting systems; the resistances are conveniently and accessibly supported in the frame in such manner that they :an be readily inspected, removed, and replaced while at the same time they are pro tectcd; and all necessary connections with the system can be readily made. The frame is adapted. within e tin limits, to receive any number of resistances or other devices, and is also capable of a variety of changes and alterations to accommodate various arrangements of the system. Thus I am enabled to use a standard frame which can be readily accommodated to systems varying with the particular service. Thus, for example, the frame can be accommodated to a car lighting system such as shown, in which there are only few translating circuits, but the same frame can also be accommodated to systems such as are used on dining cars in which there are often as many as ten dillerent translating circuits, some of which are used alternately. It will also be apparent that it, for any reason, the particular system to which my improvements have been applied is altered, the frame can be readily accommodated to such alteration.

The particular system which I have indicated in diagrammatic character and briefly described contains subjectmatter substantially similar to that disclosed in my 00- pcnding applications, Numbers 149,758 and 149,759, to which attention is directed for a more complete statement of the arrangement and operation of the system. Various modifications of my improved frame can be made without departing from the spirit of my invention, and it is to be understood. that I have used the term resistances in a broad sense, as it will be apparent that some other form of device or connection for performing certain functions in a train lighting system may be supported and arranged in, or connote l to, the frame. The term bus-bar is also us d broadly.-

The protection of the resistance tubes, briefly touched upon hereinbe'tore, is quite a important advantage oi my construction. he end connections ot the resistances which protrude from the ends of the translating tube are susceptible to breakageas are the ends of the tube itself. Since the bus-bars are anglc-shapezil, not only the ends of the resistance tubes are covered over, but the vertical. legs of thebus-bars cover over the ends. thereby atit'ording protection for the end connections and also for the ends of the tubes. At the same time, the tubes are sufliiently exposed. to permit of ready examination, and the tubes can be readily inselted, removed or replaced from the rear of the frame.

Another advantage to be noted is that; the frame lends itself readily to the reception of auxiliary resistances in addition to the resistances 18 and 20, and this without the necessity of adding additional terminals such as 40 and 42. I have shown such an additional. auxiliary resistance 48 in dotted lines and when such an additional resistance is applied, the holding screws 39 are used as means to hold such resistance and as a terminal such as 40 and 4:2. lVhen this is to be done, an insulating disk 49 is placed under the head of the upper holding screw 39 so as to insulate it from the bus-bar 15 and the wire (which in such case corresponds to the wire A1 or wire 43) is wrapped around they screw above the insulating disk. The lower screw 39, holding the resistance 22 in position, can be similarly employed as a terminal for the wire 24 and the lower end of resistance 22 by the interposition of a similar insulating disk 49.

In Fig. 5 I have shown a section illustrating a modification to be used as a substitute for the screws 39, such modification being intended to increase the facility with which the resistance can be inserted or removed. In this construction, I employ a headed pin 51 which is inserted in one of the openings 38, after which the spring 5 1 is slipped over, the shank and held in place by means of the washer 52 and screw 53. The washer 52 is adapted to fit within the porcelain tube 55 of a resistance. In inserting a resistance the pin 51 is pulled up, the resistance put in place and the pin 51 released, whereuponthe spring 54; carries the washer 52 down into the resistance tube.

he tube is thus securely positioned and the head of the member 51 serves as a terminal for the end connection. In order to remove the tube the member 51 is drawn up so as to free the washer 52 from the tube.

I claim 1. A resistance frame for car lighting systems comprising a pair of spaced bus-bars having means whereby a plurality of resistance tubes may be removably supported by and between the bus-bars. I

2. A resistance frame for car lighting systems comprising a pair of spaced busbars having means whereby a plurality of resistances may be removaibly supported between the bus-bars, said means also serving as terminals for establishing electrical connection.

3. A resistance frame for car lighting systems comprising a pair of spaced, relatively fixed bus-bars, each having a plurality of oppositely arranged retaining members, and a plurality of resistance tubes adapted to be inserted between the relatively fixed bus-bars and to be engaged by said retaining members.

4. In a device of the class described the combination of a pair of opposing bus-bar members, and one or more resistance tube members of a length permitting the same to be inserted between the bus-bar members, one set of said members having retractable means adapted to detachably support the tube members between the bus-bar members.

5. In a device of the class described the combination of a pair of opposing bus-bar members, and one or more resistance tube members of a length permitting the same to be inserted between the bus-bar members, one set of said members having retractable means adapted to serve as a means for holding the tube members between the bus-bar members or as terminals, or both.

6. A resistance frame for car lighting systems comprising a pair of spaced busbars, and a plurality of resistance tubes supported therebetween, one of said busbars being connected to a source of electrical energy, and the other of said bars being provided with means adapted to serve either as a retaining means for the tubes or as terminals. 5

7. A resistance frame for car lighting systems comprising a pair of bus-bars, end members for spacing apart said bus-bars, but insulated therefrom, a plurality of oppositely arranged holding members in said bus-bars, and resistances supported by said holding members. i

8. A resistance frame for car lighting systems comprising a pair of bus-bars, members for spacing said bus-bars apart, but insulated therefrom, means for detachably supporting resistances between the bus-bars, and terminals on the bus-bars and on the spacing members.

9. A panel board and a resistance frame comprising a pair of bus-bars and means for spacing said bus-bars apart, sald spacing means providing a means for attachment of the frame to the panel board.

10. A resistance frame for car lighting systems comprising a pair of busbars, a plurality of oppositely arranged yielding holding members in said bus-bars, and a resistance supported by said holding members.

11. A resistance frame for car lighting systems comprising a pair of bus-bars, a plurality of oppositely arranged retractable holding members in said bus-bars, and a resistance supported by said holding members.

12. A resistance frame for car lighting systems comprising a pair of bus-bars, a plurality of oppositely arranged retractable holding members in said bus-bars, a resistance supported by said holding members, said resistances being of less length than the space between the bus-bars.

In testimony whereof I have hereunto signed my name.

HARRY D. ROHMAN.

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